JP2017211986A - Method of monitoring functional states of pressure-driven actuator and pressure-driven actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to reliably monitor functional states of a pressure-driven actuator in a structurally simple manner.SOLUTION: The invention relates to a method of monitoring a functional state of a pressure-driven actuator (10) which comprises an actuator compartment (12) defined at least in portions by a flexibly deformable wall (14), the actuator being actuated by applying pressure to the actuator compartment (12) by means of an operating pressure supply (16), a work process being carried out to actuate the actuator, which process is accompanied by the actuator transitioning from a starting configuration to an end configuration. The method is characterized in that a pressure during the transition from the starting configuration to the end configuration is measured depending on time by means of a sensor apparatus (24) for measuring the pressure applied to the actuator compartment (12), and a characteristic curve (a, b, c, d) representing the progression of the pressure over time during the work process is determined and is stored in a storage apparatus (26). The invention also relates to the actuator (10) having the memory apparatus (26) for execution of the method.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for monitoring the functional state of a pressure-driven actuator as set forth in the premise of claim 1 and to a pressure-driven actuator for carrying out the method.

  One application field is an actuator driven by a negative pressure, such as a negative pressure gripper, a bellows, or a tube lifter having a lift tube, which is described in, for example, Patent Document 1 and Patent Document 2. Yet another field of application is overpressure driven actuators, such as pneumatic or hydraulic actuators and manipulators.

  Common to such actuators is that a flexible deformable actuator space is loaded with pressure in order to operate the actuator. In principle, this may be overpressure (in the case of an overpressure driven actuator) or negative pressure (in the case of a negative pressure driven actuator). The load on the actuator space is in particular carried out by a working fluid provided from an operating pressure supply (eg a pressure source, a negative pressure pump, an ejector, etc.). The working fluid can in principle have an overpressure or a negative pressure with respect to the surroundings. The working fluid can be, for example, a hydraulic fluid or a compressed gas, such as compressed air. The present invention is particularly directed to a pneumatic actuator that uses air as a working fluid.

  The actuators described above are often for incorporation into complex handling and manufacturing processes where, for example, objects must be lifted, grasped, clamped, machined, or otherwise handled. In particular, an automatically proceeding process is desired. This requires that the operations of the individual functional units are adapted to each other and performed according to need.

  In order to achieve this, the functional state of the actuator should be monitored during operation. In particular, functional data representing the functional state, for example relating to the latest operating state of the actuator, configuration, load state, etc., should be determined.

  There are many different influencing factors for such characteristic information. On the other hand, the mechanical properties of the actuator may change over time based on, for example, aging or wear of the materials used. Similarly, the hydraulic mechanical properties of the working fluid may change over time. Furthermore, the current functional state of the actuator itself also affects the measurable feature quantity. For example, the current compression state of the actuator space and / or the current deformation state of the actuator space affects its behavior when a pressure change is applied.

  In order to obtain reliable and reliable information about the functional status of individual units in complex installations, sensors with different characteristics can be arranged in different units of pressure-driven or pressure-controlled types. Are known. For example, the supply pressure of the negative pressure gripper device can be monitored (for example, Patent Document 3), or the supply compressed air supplied to the compressed air actuated ejector can be monitored (for example, Patent Document 4). Furthermore, it is known to monitor the arrival of each initial or final configuration of the actuator by means of sensors. Therefore, in order to monitor various types of functional states, a large number of sensors and data communication units and control units attached to the sensors are necessary, which may lead to higher design costs and failure.

  Patent Document 5 describes a method of operating a vacuum generating apparatus having a constituent element of the premise of claim 1 and having a suction gripper connected thereto.

International Publication No. 2005/110907 Specification US Patent Application No. 4,413,853A German Patent Application Publication No. 102014206308A1 WO20130120801A1 Specification German Patent Application No. 102007061820A1

  An object of the present invention is to enable reliable monitoring of the functional state of a pressure-driven actuator in a simple design manner.

  This problem is solved by a method for monitoring the functional state of a pressure-driven actuator according to claim 1. Correspondingly, this problem is also solved by a method for actuating a drive-type actuator according to claim 1, which has the method components described in detail below.

  The method is implemented using an actuator that is pressure driven and has a flexibly deformable actuator space. For this purpose, the actuator space is at least partly delimited by flexible walls. In particular, the wall portion is configured to be flexible and elastically deformable.

  In order to operate the actuator, the actuator space is loaded with pressure (overpressure or negative pressure). The pressure for driving the actuator is provided from the operating pressure supply.

  In order to operate the actuator, a working process is performed based on the present method, which involves the transition of the actuator from the initial configuration to the final configuration. This transition is caused by actuator space loading due to pressure. The transition from the initial configuration to the final configuration is associated with deformation of the actuator space, and in particular with deformation of the flexible wall of the actuator space.

  In order to monitor the functional state, a sensor device configured to measure the pressure loading the actuator space is utilized. With the sensor device, during the transition from the initial configuration to the final configuration, i.e. during the working process, the pressure on the actuator is measured in a time-dependent manner. For this purpose, the sensor device measures in particular the pressure generated in the actuator space. It is also conceivable to measure the pressure at the access to the actuator that is connected to the operating pressure supply.

  The monitoring of the functional state is possible because the pressure loading the actuator space is not defined only by the operating pressure supply. Rather, the temporal pressure transition of the actuator space as provided by the operating pressure supply is affected in various ways, eg material properties, the current configuration of the actuator (eg of the actuator space being loaded). It is influenced by the volume, the deformation state of the actuator space, the deformation state or compression state of the wall section that divides the actuator space, and the load state acting on the actuator (for example, based on the weight of the object to be contacted). Since the actuator space is at least sectioned by a wall that can be flexibly deformed, the mechanical properties of the wall and the resulting deformation of the actuator space can vary relatively depending on the pressure. . The consequence is that the actuators of the type described above with flexible walls have a characteristic dependence on the functional state of the pressure loading the actuator space.

  Therefore, information on the functional state and load state of the actuator can be derived from the measured values of the pressure loading the actuator space at various times. And functional data can be determined using a sensor measurement result.

  The function data to be determined represents the function state. Functional state and functional data can target a variety of information. This type of information is listed below as an example.

  The current operating state of the actuator, e.g. retracted and extended (e.g. final position state of the drive actuator), gripping state or released state (e.g. negative pressure gripping device).

  The current configuration and / or deformation of the actuator or of the walls that delimit the actuator space, for example the compression of the pressure space, the degree of elastic deformation (for example of a bellows-type actuator or a deformable negative pressure suction machine).

  The current load state of the actuator, for example by the weight force or inertial force of an object operated (eg gripped, handled) by the actuator; in particular the recognition of the presence or absence of the object to be operated.

  -The current wear state of the actuator, for example changed material properties such as stiffness and elasticity due to material fatigue (for example in the case of bellows, lift hoses or negative pressure grippers), the changed coefficient of friction of the material areas that cause friction with each other. Furthermore, wear can lead to changes in the sealing quality of overpressure or negative pressure actuators.

  By this method, various information can be determined by only one sensor device (for example, only one pressure sensor). Compared with a system having a complicated sensor device including a plurality of sensors, failure occurrence can be reduced. The determined function data can be used to control the actuator according to the need. In particular, it is possible to adjust the operating pressure supply depending on the time course of the measured pressure. For example, if the actuator is a negative pressure gripping device, an optimum force can be exerted on each type of object for the desired handling during the gripping process (work process). As such, surface damage and deformation can be avoided in the case of an object that is easily damaged. In addition, the monitoring of temporal pressure transitions also enables monitoring and evaluation of work processes. For example, the characteristics of pressure transitions determine whether an object is gripped according to the application in a negative pressure gripper as an actuator, how heavy the object is, and / or how large the object is can do.

  In principle, information on the functional state can also be determined from measurements of other fluid characteristic quantities. In that sense, it is possible in principle to measure the volumetric flow rate flowing into and / or out of the actuator space. Functional data related to the above-described characteristics can also be determined from such measurement data.

  In particular, it is preferable that the work process is executed under the action of a load generated when the actuator is operating in accordance with the application. In that sense, the measurement is performed during the original working process of the actuator, for example, during handling of an object or driving of the device by the actuator. In that sense, it is not necessary to interrupt the use according to the application in order to monitor the functional state.

  In order to be able to reliably monitor changes in the measured pressure over time, in one preferred embodiment, the volumetric flow rate of the working fluid provided from the operating pressure supply is determined by the amount of actuator space and / or It can be adapted to the mechanical properties. Therefore, it may be intended that a throttle valve, a flow resistance, a flow restrictor, and the like are interposed between the operating pressure supply unit and the actuator space. Thereby, the change of the volume flow rate can be further reduced, and the change of the pressure can be suppressed. As a result, it is possible to prevent the monitoring from being inaccurate due to the rapid change of the pressure over time.

  According to the present invention, a characteristic curve representing a temporal transition of pressure during a work process is determined and stored in a memory device. The recorded characteristic curves allow for the estimation of various types of influence factors and associated functional states. In particular, different types of influences act on different regions of the characteristic curve, for example at different pressure levels and / or at different times. In the course of the characteristic curve, for example, changes in the material properties of the actuator (e.g. based on aging processes and / or wear processes) can be distinguished from actuator loads (e.g. due to the force of the weight of the object). This is especially true for actuators having an actuator space separated (at least in part) by a flexible wall. Since the mechanical properties of the wall change with the deformation state, the temporal pressure transition at the beginning of the work process differs from the temporal pressure transition at the end of the work process in a characteristic way. Different functional states therefore result in characteristic curves that are well distinguishable.

  One simple method is not to determine a continuous characteristic curve, but a discrete reference in which the pressure measured at a defined time interval from the start of the work process is stored in a memory device. This is made possible by comparing the value and / or determining the difference from the stored reference value.

  In another aspect, a continuous characteristic curve is determined and recorded, but only a defined number of points of the characteristic curve correspond to a corresponding number of discrete reference points (measured from the start of the work process). And / or a difference from the reference value is determined. Although monitoring of the characteristic curve at discrete defined points may be sufficient, it can be attributed to various effects (material aging, loading, deformation, etc.) typically in the characteristic areas of the characteristic curve. It is because it affects.

  Strict monitoring is possible by comparing the determined characteristic curve with a reference characteristic curve stored in a memory device and / or determining a difference from the reference characteristic curve. From the deviation from the reference characteristic curve, various types of functional states can be determined, as will be explained in more detail later.

  The method can preferably be further configured as an actuating method for the actuator. For this purpose, in particular, the operating pressure supply is controlled in such a way that the pressure loading the actuator space responds to a respective predetermined target value at fixedly defined time intervals (measured from the start of the work process) and / or It may be intended that the load on the actuator space due to pressure is controlled (for example by means of a pre-valve valve device). It is conceivable that the control is performed so that the difference between the predetermined target values is a maximum allowable error.

  In particular, it can be controlled so that the measured pressure (and / or the characteristic curve to be determined) substantially follows the desired target characteristic curve. In particular, it is possible to control so that the measured characteristic curve representing the pressure changes within an acceptable range from the target characteristic curve during the work process.

  To obtain comparable data, the operating pressure supply provides a predefined output and / or a predefined volume flow rate of the working fluid to operate the actuator when the work process is performed. Preferably it is intended. This provides a reproducible operating pressure supply and ensures comparable measurements.

  For further developed embodiments, the reference characteristic curve can be determined in a calibration process. The calibration process is carried out in addition to the work process, in particular directly after a defined number of work processes have been carried out or at the start of the first use of the actuator at the higher level equipment. In the calibration process, it is particularly intended that the actuator is loaded with a defined and reproducible load, for example under the action of a defined and reproducible force. For example, in the case of an overpressure drive type drive device as an actuator, this may be a neutral state that is an idling state without a load. In the calibration process in particular, it is also contemplated that the operating pressure supply provides a defined output and / or a defined volumetric flow rate of the working fluid. As in the work process, the calibration process is characterized in that the actuator moves from an initial configuration to a final configuration. During the transition, the time dependence of the pressure loading the actuator space is determined in the form of a reference characteristic curve representing the temporal pressure transition and stored in the memory device.

  For further developed embodiments of the method, functional data is determined each time from the pressure measured as a function of time. This can preferably be done with a control device. The function data represents the function state of the actuator. For example, the information listed at the beginning can be determined as functional data from the transition of the characteristic curve, the magnitude of the difference from the reference value, and / or the magnitude of the measured characteristic curve difference with respect to the reference characteristic curve.

  In particular, it is preferable to determine the load due to the force acting on the actuator from the time dependence of the measured pressure. For example, in the case of a lifting actuator (eg, a tube lifter), the weight (or weight force) of the object being handled can be determined.

  For further developed embodiments of the method, it is intended that a number of work processes are performed sequentially. These working processes are configured to repeat in particular periodically, i.e. after the actuator has reached the final configuration, it again moves to the initial configuration. For example, the determined characteristic curve can be averaged. It is also conceivable to perform the calibration process as described above after a defined point in time and / or after a defined number of work processes.

  The problems imposed at the outset are also solved by pressure-driven (or pressure-driven actuators). The actuator is configured to be operable with a load in the actuator space at pressure (overpressure or negative pressure), and the actuator transitions from an initial configuration to a final configuration with a load at pressure (working) process). The actuator space is partitioned by a wall that can be flexibly deformed. In particular, the wall portion is elastically deformable. The wall deforms during the transition from the initial configuration to the final configuration. In accordance with the method described above, a sensor device is provided which is configured to measure the pressure loading the actuator space in a time-dependent manner. The sensor device may in particular be an actuator space or a pressure sensor at the access to the actuator space.

  For a further developed embodiment of the actuator, a control device is provided which cooperates with the sensor device and is configured and / or programmed to implement a method for monitoring the functional state of the actuator as described above. It may be. The control device may be integrated in a sensor microcontroller, for example. In particular, the control device may store a computer program for controlling the control device in order to implement the method described above.

  The control device may be configured to control the operating pressure supply of the actuator depending on the measured pressure. As described above, in particular, the control of the operating pressure supply unit can be performed such that the measured characteristic curve is kept within a desired allowable range with respect to the target characteristic curve.

  The pressure-driven actuator may in principle be any kind of actuator that can be actuated by a pressure load in the actuator space, as explained at the outset. For example, the actuator may be configured as an overpressure driven or negative pressure driven actuator.

  One preferred field of application is in particular an actuator configured as a negative pressure gripping device in which the suction space forms the actuator space described above. The suction space can be loaded with negative pressure to grip the object. In particular, the negative pressure gripping device has a contact surface including a suction opening communicating with the suction space. The abutting surface provided with the suction opening abuts on the object to grip the object.

  Yet another preferred embodiment is that the actuator is configured as a tube lifter. The tube lifter includes a lift tube having a tube internal space that forms an actuator space. The lift tube is configured as a flexible deformable wall so that the lift tube is shortened by negative pressure loading the tube interior space, that is, it is possible to move from the extended initial configuration to the final contracted configuration It is. In this kind of tube lifter, it is preferable that the weight of the object lifted by the tube lifter can be determined from the characteristic curve.

  One particularly preferred field of application is the so-called fluid elastomer actuator. It has a flexible wall made of elastomer surrounding the actuator space. The actuator space has in particular an access for supplying and discharging working fluid. This actuator space is preferably closed to the surroundings by a wall made of an elastomer. Fluidic elastomer actuators can handle objects, for example, by a pressure-induced transition from an initial configuration to a final configuration.

  Next, the present invention will be described in detail with reference to the drawings. The drawing shows:

1 schematically shows an actuator according to the invention for carrying out the method of the invention. It is a graph as an example which shows the characteristic curve about various operating conditions of an actuator. It is a graph as an example for demonstrating the comparison with the reference value in the defined reference time. It is a graph as an example for demonstrating another influence factor with respect to a characteristic curve. FIG. 6 shows yet another embodiment of an actuator according to the invention in an initial configuration. FIG. 6 is a diagram showing the actuator of FIG. 5 in a final configuration.

  In the following description and drawings, the same reference numerals are used for the same or mutually corresponding constituent elements.

  FIG. 1 shows a schematic diagram of a pressure-driven actuator 10. As an example, the actuator 10 is configured as a negative pressure gripper. This actuator has an actuator space 12 delimited by a wall 14 that can be flexibly deformed. In the illustrated example, the flexibly deformable wall portion 14 is configured as a flexibly deformable bellows.

  In order to load the actuator space 12 with pressure, the actuator space 12 is pressure-connected and / or fluidly connected to the operating pressure supply 16.

  In FIG. 1, the actuator 10 configured as a negative pressure gripping device has a contact surface 18 having a suction opening 20 communicating with the actuator space 12. In order to grip the object 22, the contact surface 18 of the suction opening is applied to the object 22, and the actuator space 12 is loaded with a negative pressure.

  However, actuators having other types of actuator spaces 12, such as a lift tube, can also be applied, in which case the actuator space 12 is surrounded by a lift tube wall (for example, corresponding to the wall 14). Similarly, the actuator 10 may be configured as a fluid-type elastomer actuator that changes its shape depending on a load due to pressure.

  In order to operate the actuator 10, the actuator space 12 is loaded with pressure. If this is a negative pressure actuated actuator as shown in FIG. 1, the actuator space 12 is loaded with negative pressure relative to the surroundings.

  The actuator 10 has a sensor device 24 (in this example, a pressure sensor) configured to measure the pressure that loads the actuator space 12. Furthermore, the actuator 10 can have a control device 26 that cooperates with the sensor device 24 so that the pressure loading the actuator space 12 can be measured in a time-dependent manner (see FIG. 1). In particular, the actuator 10 can include a memory device as a component of the control device, for example. The measured data can be stored in the memory device.

  The functional state of the actuator 10 can be monitored during the execution of the work process. In order to execute the work process, the actuator space 12 is loaded with pressure (negative pressure in the illustrated example) by the operating pressure supply 16. As a result, the actuator moves from the initial configuration to the final configuration. In the example of FIG. 1, the initial configuration is an extended configuration of the wall portion 14 that can be flexibly deformed, as shown in FIG. 1. When the actuator space 12 is evacuated, the configuration of the actuator 10 (strictly, the wall 14 or bellows in FIG. 1) changes due to compression along the compression direction 28. The final configuration is reached when the bellows 14 is fully crimped according to its material and geometric properties. In that sense, the transition from the initial configuration to the final configuration is associated with the deformation of the flexible wall 14.

  Depending on the time at which the sensor device 24 loads the pressure on the actuator space 12 or the pressure generated in the actuator space 12, depending on the time, the start of the transition from the initial configuration to the final configuration. From time to time it can be measured. The temporal pressure transition can be recorded in the form of a characteristic curve representing the dependence of pressure on time, and can be stored, for example, in the control device 26 or memory device.

  2 to 4 show various characteristic curves and the influence of various operating states of the actuator 10 on the characteristic curves.

For example, FIG. 2 shows a characteristic curve of the pressure loading the actuator space 12 for various work processes. Each work process starts here at time t _A = 0 and ends at time t _E.

  For example, the operating pressure supply 16 can be controlled to provide a constant output throughout the work process. At this time, time point tE indicates the end of the work process and is defined by the arrival of the final configuration of the actuator.

  In FIG. 2, the various work processes assigned to the various characteristic curves are distinguished, for example, by the mass of the object 22 gripped by the actuator 10. Different masses of the object 22 result in different loading conditions for the actuator 10. In the illustrated example of FIG. 1, various load conditions act on various weight forces acting on the object 22 that is attracted to resist the transition of the actuator space 12 from the initial configuration to the final configuration. It corresponds to.

  As clearly seen in FIG. 2, the characteristic curves for the various loading conditions (in this example the mass of the object 22) differ from each other in a characteristic way, ie the zones X and Y of the work process (ie the characteristic curve transitions). Various areas) exist. As an example, characteristic curves a, b, c, d for various masses are shown.

  This makes it possible to determine what load condition the actuator 10 is exposed to by analyzing the transition of the recorded characteristic curve. That is, by measuring the characteristic curve, for example, the functional state such as the mass of the object being grasped can be determined.

Since the characteristic curves for the various load conditions are different from each other in the characteristic zones X and Y, the various characteristic curves are not defined throughout the work process, but are defined discrete reference times t ₁ and t _2. It may be sufficient to evaluate at. This is clearly shown in FIG. From the characteristic curve values at the time points t ₁ and t ₂ , the functional state of interest (the mass of the object 22 in this example) can be similarly determined based on characteristic transitions in the areas X and Y. it can. This means that in the examples of FIGS. 2 and 3, the characteristic curves a, b, c, d (see FIG. 2) can already be distinguished by characteristic values at the reference times t ₁ and t _2. .

  Various types of information regarding the functional state of the actuator 10 can be determined by measuring the pressure applied to the actuator 12 depending on time. To that end, it can be used that different influence factors often affect different characteristic areas of the characteristic curve. This is clearly shown in FIG. Shown are various series of characteristic curves for different load conditions of the actuator, again with different weight forces. As described with reference to the example of FIG. 2, the characteristic curves in the zone X of the work process differ from one another in a characteristic manner depending on the load due to weight.

  In FIG. 4, both characteristic curves to which reference numerals e1 and e2 are attached correspond to load states with the same weight or the same mass. In that sense, the characteristic curves e1 and e2 substantially coincide with each other in the area X described above.

  However, in the case of FIG. 4, the characteristic curves e1 and e2 are recorded in two functional states of the actuator 10, which are distinguished in terms of the degree of deformability of the actuator space 12. The degree of deformability is affected, for example, by the configuration of the wall 14 that can be flexibly deformed. For example, if it is a bellows, compression can be performed under deformation until the individual creases are in a compressed state of the material abutting each other. Similarly, material fatigue and material wear can also lead to changes in mechanical properties and associated deformation behavior. As can be seen in FIG. 4, the characteristic curves e1 and e2 are distinguished in a characteristic zone Z of the work process which is different from the zone X.

  In summary, by analyzing the characteristic curves in both the section X and the section Z, it is possible to determine information on the load state of the actuator, and at the same time, information on the degree of deformability or, in some cases, information on material fatigue.

  The characteristic curve can be stored and evaluated as a data set by the control device 26, for example. As explained at the outset, the evaluation can include, for example, a comparison with a reference characteristic curve. The function data that characterizes the functional state of the actuator can be determined from the characteristic curve or the value of the characteristic curve at the defined reference time. For this purpose, the control device 26 can have a correspondingly configured evaluation unit with the processor.

  Figures 5 and 6 show yet another preferred field of application. Here, the actuator 10 is configured as a fluid elastomer actuator. It has an actuator space 12 surrounded by a wall 14 made of elastomer. The actuator space 12 can be loaded with working fluid through the access portion 30. In the illustrated example, the actuator includes two finger-like areas, each of which is completely surrounded by the wall 14 (except for the access part 30), in particular with respect to the periphery. The defined and / or delimited region 32 of the wall 14 may be configured in a crease shape (see FIG. 5).

  In FIG. 5, the actuator 10 is shown in an initial configuration. When the actuator space 12 is loaded with pressure, the flexibly deformable wall 14 of the actuator 10 extends. This leads to a change in the shape of the actuator 10. For example, if the defined region 32 of the wall portion 14 is configured in a fold shape, the region 32 configured in the fold shape is another region of the wall portion 14 that can be flexibly deformed when subjected to a pressure load. Elongate more than. As a result, the fluid elastomer actuator 10 assumes the final configuration shown in FIG. This final configuration is distinguished from the initial configuration with respect to its overall shape. This can be used to grip the object 22. In the illustrated example, when the final configuration is established, the finger-shaped area of the actuator 10 surrounds the object 22 (see FIG. 6).

Claims (11)

A method for monitoring the functional state of a pressure-driven actuator (10) having an actuator space (12) at least sectioned by a flexibly deformable wall (14), said actuator (10) operating Operated by a pressure load on the actuator space (12) by the pressure supply (16),
A work process involving the transition of the actuator (10) from an initial configuration to a final configuration is performed to operate the actuator (10);
The pressure is measured as a function of time by a sensor device (24) for measuring the pressure loading the actuator space (12) during the transition from the initial configuration to the final configuration;
In such a method, a characteristic curve (a, b, c, d) representing the time course of pressure during the work process is determined and stored in the memory device (26),
The determined characteristic curve is compared with a reference characteristic curve stored in the memory device (26) and / or a difference from the reference characteristic curve is determined;
A method in which functional data representing a functional state of the actuator (10) is determined from a transition of a characteristic curve and / or a difference from a reference characteristic curve. The pressure is measured only at a defined time interval (t ₁ ; t ₂ ) from the start of the work process, compared with the reference value stored in the memory device (26) and / or the difference from the reference value. The method of claim 1, wherein: is determined. The pressure is measured continuously, a defined and limited number of pressure reference values and characteristic curves are compared and / or the difference from the reference values for discrete reference time points (t ₁ , t ₂ ) The method of claim 1, wherein: is determined.   The pressure applied to the actuator space (12) responds to a predetermined target value at a time interval defined from the start of the work process, or a predetermined tolerance is at most the difference from the predetermined target value. The operating pressure supply (16) is controlled and / or the load at the pressure of the actuator space (12) is controlled as such. The method described in 1.   The operating pressure supply (16) provides a defined output and / or a defined volume flow of working fluid to operate the actuator (10) to perform a working process, The method according to claim 1.   In addition to a working process, the actuator is loaded with a defined and reproducible load so that the working pressure supply (16) provides a defined output and / or a defined volumetric flow of working fluid. A process is performed, the actuator (10) transitions from an initial configuration to a final configuration, and the time dependence of pressure is determined in the form of a reference characteristic curve representing a temporal pressure transition and the memory device (26 The method according to any one of claims 1 to 5, wherein the method is stored.   The method according to claim 1, wherein a force acting as a load on the actuator is determined from a time transition of the measured pressure.   8. A method according to any one of the preceding claims, characterized in that a number of work processes are carried out such that they are repeated periodically and are continuous.   Pressure having an actuator space (12) that is at least sectioned by a wall (14) that can be flexibly deformed so that the actuator (10) can be operated by a load with the pressure of the actuator space (12). A drive type actuator (10), wherein the actuator (10) moves from an initial configuration to a final configuration while deforming the wall portion (14) that can be flexibly deformed, and the actuator space (12) 9. In such an actuator, which is provided with a sensor device (24) for measuring in a time-dependent manner the pressure applied to the element, configured to carry out the method according to any one of claims 1-8 A pressure-driven actuator (1) characterized in that a control device (26) is provided. ).   10. The negative pressure gripping device according to claim 9, wherein the actuator (10) is a negative pressure gripping device comprising a suction space (12) that forms the actuator space that can be loaded with negative pressure to grip an object (22). Pressure-driven actuator (10).   The actuator is a tube lifter having a tube inner space of a lift tube forming the actuator space, and the lift tube shifts from an initial configuration expanded by a negative pressure applied to the tube internal space to a final configuration contracted. 10. A pressure driven actuator (10) according to claim 9, which is possible.